试了一下，供参考：

proc sort data=a;by stkcd date;run;

data b;
        set a;
        by stkcd;
        retain jm;
        if first.stkcd then jm=0;
        if substr(put(date,best6.),5,2) in ("02","05","08","11") then jm=msmvttl;
        jm1=lag(jm);
        if jm=0 then jm1=0;
        if jm1^=0 then gx=(msmvttl/jm1)*pb;
run;

为了这100金币，折腾了一下午，总算是把程序调试出来了。楼上的两个帖子的CODE完全不行，没那么简单。加了两个附件： 名字都是STOCK, 一个是SAS源程序（把后缀名改为.sas就可以运行），一个是运行结果（excel 文件）。半天时间的劳动，希望楼主信守承诺。我还指望着用这金币买书呢。如果有任何问题，站内联系。谢谢。以下是程序：



****author: thinman66*****************;
****date:   9/3/2013******************;
****purpose: earning 100 currencies on bbs.pingu.org******************;

data stock;
input stkcd date $  msmvttl pb;
cards;
1 199312 6000 2
1 199401 6300 2
1 199402 6200 2
1 199403 6000 3
1 199404 6400 3
1 199405 6700 3
1 199406 7000 5
1 199407 6500 5
1 199408 6800 5
1 199409 7100 2
1 199410 6750 2
1 199411 6000 2
1 199412 6000 2
1 199501 6300 2
1 199502 6200 2
1 199503 6000 3
1 199504 6400 3
1 199505 6700 3
1 199506 7000 5
1 199507 6500 5
1 199508 6800 5
1 199509 7100 2
1 199510 6750 2
1 199511 6000 2
3 199312 6000 2
3 199401 6300 2
3 199402 6200 2
3 199403 6000 3
3 199404 6400 3
3 199405 6700 3
3 199406 7000 5
3 199407 6500 5
3 199408 6800 5
3 199409 7100 2
3 199410 6750 2
3 199411 6000 2
3 199412 6000 2
3 199501 6300 2
3 199502 6200 2
3 199503 6000 3
3 199504 6400 3
3 199505 6700 3
3 199506 7000 5
3 199507 6500 5
3 199508 6800 5
3 199509 7100 2
3 199510 6750 2
3 199511 6000 2
;
run;

data stock;
set stock;
year=input(substr(date, 1, 4), ??best.);
month=input(substr(date, 5, 2), ??best.);
if month in (1, 2, 3) then quarter=1;
else if month in (4,5,6) then quarter=2;
else if month in (7,8,9) then quarter=3;
else if month in (10,11,12) then quarter=4;
run;

data stock;
set stock;
if month=3 then endmv1=msmvttl;
else if month=6 then endmv2=msmvttl;
else if month=9 then endmv3=msmvttl;
else if (month=11 or month=12) then endmv4=msmvttl;
run;

proc sort data=stock ;
by stkcd year month;
run;
data yr93;
set stock;
if year=1993 ;
run;

data yr94;
set stock;
if year=1994 ;
run;

data yr95;
set stock;
if year=1995 ;
run;



Data yr94( Drop = _: ) ;
Set yr94 ( Rename = ( endmv1 = _endmv1 endmv2 = _endmv2   endmv3 = _endmv3 endmv4 = _endmv4  ) ) ;
Retain endmv1 endmv2 endmv3 endmv4 ;

If not missing( _endmv1   ) then endmv1   = _endmv1 ;
If not missing( _endmv2 ) then endmv2 = _endmv2;
If not missing( _endmv3   ) then endmv3   = _endmv3;
If not missing( _endmv4 ) then endmv4 = _endmv4;

run ;

Data yr95( Drop = _: ) ;
Set yr95 ( Rename = ( endmv1 = _endmv1 endmv2 = _endmv2   endmv3 = _endmv3 endmv4 = _endmv4  ) ) ;
Retain endmv1 endmv2 endmv3 endmv4 ;

If not missing( _endmv1   ) then endmv1   = _endmv1 ;
If not missing( _endmv2 ) then endmv2 = _endmv2;
If not missing( _endmv3   ) then endmv3   = _endmv3;
If not missing( _endmv4 ) then endmv4 = _endmv4;

run ;

proc sort data=yr94;
by         descending endmv1  descending endmv2 descending endmv3 descending endmv4 ;
run;
proc sort data=yr95;
by         descending endmv1  descending endmv2 descending endmv3 descending endmv4 ;
run;

Data yr94( Drop = _: ) ;
Set yr94 ( Rename = ( endmv1 = _endmv1 endmv2 = _endmv2   endmv3 = _endmv3 endmv4 = _endmv4  ) ) ;
Retain endmv1 endmv2 endmv3 endmv4 ;

If not missing( _endmv1   ) then endmv1   = _endmv1 ;
If not missing( _endmv2 ) then endmv2 = _endmv2;
If not missing( _endmv3   ) then endmv3   = _endmv3;
If not missing( _endmv4 ) then endmv4 = _endmv4;

run ;

Data yr95( Drop = _: ) ;
Set yr95 ( Rename = ( endmv1 = _endmv1 endmv2 = _endmv2   endmv3 = _endmv3 endmv4 = _endmv4  ) ) ;
Retain endmv1 endmv2 endmv3 endmv4 ;

If not missing( _endmv1   ) then endmv1   = _endmv1 ;
If not missing( _endmv2 ) then endmv2 = _endmv2;
If not missing( _endmv3   ) then endmv3   = _endmv3;
If not missing( _endmv4 ) then endmv4 = _endmv4;

run ;



data combine;
set yr93 yr94 yr95;
run;

data combine;
set combine;
if quarter=4 then lastq=endmv3;
else if quarter=3 the lastq=endmv2;
else if quarter=2 the lastq=endmv1;
run;


data combine (drop=endmv1-endmv4);
set combine;
if (year=1994 and quarter=1) or (year=1995 and quarter=1) then lastq=endmv4;
***sjlv is         市净率        ***********************;

sjlv=( msmvttl/lastq)*pb;
run;